the primary reason for raising the rails is for tie rod clearance since everything else is raised ..... all at NO ADDITIONAL cost from HDK
while Ross's doesn't utilize them, HDK motor perches combined with HDK/Schumaker ploy-spool motor mounts for ALL the popular Mopar powerplants are available and interchangeable
sorry for the self-serving promo....but it is a FAQ via privite message and e-mail